+use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::higher::VecArgs;
+use clippy_utils::source::snippet_opt;
+use clippy_utils::ty::{implements_trait, type_is_unsafe_function};
+use clippy_utils::usage::UsedAfterExprVisitor;
+use clippy_utils::{get_enclosing_loop_or_closure, higher};
+use clippy_utils::{is_adjusted, iter_input_pats};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{def_id, Expr, ExprKind, Param, PatKind, QPath};
use rustc_lint::{LateContext, LateLintPass, LintContext};
use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::{self, Ty};
+use rustc_middle::ty::{self, ClosureKind, Ty};
use rustc_session::{declare_lint_pass, declare_tool_lint};
-use crate::utils::{
- implements_trait, is_adjusted, iter_input_pats, snippet_opt, span_lint_and_sugg, span_lint_and_then,
- type_is_unsafe_function,
-};
-
declare_clippy_lint! {
/// **What it does:** Checks for closures which just call another function where
/// the function can be called directly. `unsafe` functions or calls where types
/// **Known problems:** If creating the closure inside the closure has a side-
/// effect then moving the closure creation out will change when that side-
/// effect runs.
- /// See rust-lang/rust-clippy#1439 for more details.
+ /// See [#1439](https://github.com/rust-lang/rust-clippy/issues/1439) for more details.
///
/// **Example:**
/// ```rust,ignore
///
/// **Why is this bad?** It's unnecessary to create the closure.
///
- /// **Known problems:** rust-lang/rust-clippy#3071, rust-lang/rust-clippy#4002,
- /// rust-lang/rust-clippy#3942
+ /// **Known problems:** [#3071](https://github.com/rust-lang/rust-clippy/issues/3071),
+ /// [#3942](https://github.com/rust-lang/rust-clippy/issues/3942),
+ /// [#4002](https://github.com/rust-lang/rust-clippy/issues/4002)
///
///
/// **Example:**
match expr.kind {
ExprKind::Call(_, args) | ExprKind::MethodCall(_, _, args, _) => {
for arg in args {
- check_closure(cx, arg)
+ // skip `foo(macro!())`
+ if arg.span.ctxt() == expr.span.ctxt() {
+ check_closure(cx, arg);
+ }
}
},
_ => (),
}
}
-fn check_closure(cx: &LateContext<'_>, expr: &Expr<'_>) {
- if let ExprKind::Closure(_, ref decl, eid, _, _) = expr.kind {
+fn check_closure<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ if let ExprKind::Closure(_, decl, eid, _, _) = expr.kind {
let body = cx.tcx.hir().body(eid);
let ex = &body.value;
+ if ex.span.ctxt() != expr.span.ctxt() {
+ if decl.inputs.is_empty() {
+ if let Some(VecArgs::Vec(&[])) = higher::vec_macro(cx, ex) {
+ // replace `|| vec![]` with `Vec::new`
+ span_lint_and_sugg(
+ cx,
+ REDUNDANT_CLOSURE,
+ expr.span,
+ "redundant closure",
+ "replace the closure with `Vec::new`",
+ "std::vec::Vec::new".into(),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ // skip `foo(|| macro!())`
+ return;
+ }
+
if_chain!(
- if let ExprKind::Call(ref caller, ref args) = ex.kind;
+ if let ExprKind::Call(caller, args) = ex.kind;
if let ExprKind::Path(_) = caller.kind;
let fn_ty = cx.typeck_results().expr_ty(caller);
- if matches!(fn_ty.kind, ty::FnDef(_, _) | ty::FnPtr(_) | ty::Closure(_, _));
+ if matches!(fn_ty.kind(), ty::FnDef(_, _) | ty::FnPtr(_) | ty::Closure(_, _));
if !type_is_unsafe_function(cx, fn_ty);
if compare_inputs(&mut iter_input_pats(decl, body), &mut args.iter());
then {
- span_lint_and_then(cx, REDUNDANT_CLOSURE, expr.span, "redundant closure found", |diag| {
- if let Some(snippet) = snippet_opt(cx, caller.span) {
+ span_lint_and_then(cx, REDUNDANT_CLOSURE, expr.span, "redundant closure", |diag| {
+ if let Some(mut snippet) = snippet_opt(cx, caller.span) {
+ if_chain! {
+ if let ty::Closure(_, substs) = fn_ty.kind();
+ if let ClosureKind::FnMut = substs.as_closure().kind();
+ if UsedAfterExprVisitor::is_found(cx, caller)
+ || get_enclosing_loop_or_closure(cx.tcx, expr).is_some();
+
+ then {
+ // Mutable closure is used after current expr; we cannot consume it.
+ snippet = format!("&mut {}", snippet);
+ }
+ }
diag.span_suggestion(
expr.span,
- "remove closure as shown",
+ "replace the closure with the function itself",
snippet,
Applicability::MachineApplicable,
);
);
if_chain!(
- if let ExprKind::MethodCall(ref path, _, ref args, _) = ex.kind;
+ if let ExprKind::MethodCall(path, _, args, _) = ex.kind;
// Not the same number of arguments, there is no way the closure is the same as the function return;
if args.len() == decl.inputs.len();
cx,
REDUNDANT_CLOSURE_FOR_METHOD_CALLS,
expr.span,
- "redundant closure found",
- "remove closure as shown",
+ "redundant closure",
+ "replace the closure with the method itself",
format!("{}::{}", name, path.ident.name),
Applicability::MachineApplicable,
);
let actual_type_of_self = &cx.typeck_results().node_type(self_arg.hir_id);
if let Some(trait_id) = cx.tcx.trait_of_item(method_def_id) {
- if match_borrow_depth(expected_type_of_self, &actual_type_of_self)
+ if match_borrow_depth(expected_type_of_self, actual_type_of_self)
&& implements_trait(cx, actual_type_of_self, trait_id, &[])
{
return Some(cx.tcx.def_path_str(trait_id));
cx.tcx.impl_of_method(method_def_id).and_then(|_| {
//a type may implicitly implement other type's methods (e.g. Deref)
- if match_types(expected_type_of_self, &actual_type_of_self) {
- return Some(get_type_name(cx, &actual_type_of_self));
+ if match_types(expected_type_of_self, actual_type_of_self) {
+ Some(get_type_name(cx, actual_type_of_self))
+ } else {
+ None
}
- None
})
}
fn match_borrow_depth(lhs: Ty<'_>, rhs: Ty<'_>) -> bool {
- match (&lhs.kind, &rhs.kind) {
- (ty::Ref(_, t1, mut1), ty::Ref(_, t2, mut2)) => mut1 == mut2 && match_borrow_depth(&t1, &t2),
+ match (&lhs.kind(), &rhs.kind()) {
+ (ty::Ref(_, t1, mut1), ty::Ref(_, t2, mut2)) => mut1 == mut2 && match_borrow_depth(t1, t2),
(l, r) => !matches!((l, r), (ty::Ref(_, _, _), _) | (_, ty::Ref(_, _, _))),
}
}
fn match_types(lhs: Ty<'_>, rhs: Ty<'_>) -> bool {
- match (&lhs.kind, &rhs.kind) {
+ match (&lhs.kind(), &rhs.kind()) {
(ty::Bool, ty::Bool)
| (ty::Char, ty::Char)
| (ty::Int(_), ty::Int(_))
}
fn get_type_name(cx: &LateContext<'_>, ty: Ty<'_>) -> String {
- match ty.kind {
+ match ty.kind() {
ty::Adt(t, _) => cx.tcx.def_path_str(t.did),
- ty::Ref(_, r, _) => get_type_name(cx, &r),
+ ty::Ref(_, r, _) => get_type_name(cx, r),
_ => ty.to_string(),
}
}
for (closure_input, function_arg) in closure_inputs.zip(call_args) {
if let PatKind::Binding(_, _, ident, _) = closure_input.pat.kind {
// XXXManishearth Should I be checking the binding mode here?
- if let ExprKind::Path(QPath::Resolved(None, ref p)) = function_arg.kind {
+ if let ExprKind::Path(QPath::Resolved(None, p)) = function_arg.kind {
if p.segments.len() != 1 {
// If it's a proper path, it can't be a local variable
return false;
projects / rust.git / blobdiff